Good Filters, Bad Filters: What Happens When Dirty Filters Are Left in Place

Everyone knows that keeping clean filters in an air handling system is important to maintaining good indoor air quality. What everyone may not know is that leaving dirty filters in place can have an equally negative impact on indoor air quality, becoming a significant source of indoor air pollution. A recently published review of studies conducted by independent researchers throughout the last twenty years conclusively demonstrates that dirty filters are a key contributor to poor indoor air quality. The studies show that the problem was not with the filters themselves, their installation, or their location in the system, but with... Read More

How’s the Weather Inside?

The relationship of the thermal environment inside a building to the comfort, welfare, and productivity of people is a significant and sometimes overlooked component of facility design. Typically, when we think of thermal comfort, we most likely consider temperature alone. However, while temperature does have the most dramatic effect on our thermal environment, it is only one of several important components. Building surface temperatures, humidity, and air velocity (drafts) all bear directly on a person’s comfort. Since each of these elements plays an important role, we must address each of them in the design of heating, ventilating, and air conditioning... Read More

Pools: Swimming in the Details

Natatoriums can be a source of great enjoyment for swimmers, but also a source of frustration and high levels of maintenance for Owners, if not designed and constructed properly. Many factors must be considered when designing a comfortable pool environment such as humidity control, air flow distribution, and material selection. Air with a high level of entrained moisture will negatively affect comfort and, in extreme circumstances, the health of the occupants. Additionally, the moisture in the air will condense on cooler surfaces such as walls, exterior doors, and windows when surface temperatures drop below the dew point. This condensation can... Read More